Digital control loops in control systems such as switching power supplies, servo loops and robotic controllers may include a proportional-integral-derivative (PID) filter. Selection of the gain to apply to error values within a proportional-integral-derivative filter can impact a variety of architectural and performance factors for the control loop, including transient and quiescent response, transitions between consecutive steps, gain coverage, positive and negative code symmetry, step increment size near zero, code space and allocation, cost and power.
There is, therefore, a need in the art for an improved technique of setting error gain within a proportional-integral-derivative filter for digital control loops.